[Ecls-list] wrong value for (float-sign -0.0)

[Waldek Hebisch]

Gabriel Dos Reis wrote:
> 
> Hi Juanjo,
> 
>   ECL reports wrong value for the sign of -0.0.
> 
>   > *features*
>   (:LINUX :FORMATTER :IEEE-FLOATING-POINT :RELATIVE-PACKAGE-NAMES :DFFI
>    :CLOS-STREAMS :CMU-FORMAT :UNIX :ECL-PDE :DLOPEN :CLOS :BOEHM-GC :ANSI-CL
>    :COMMON-LISP :ECL :COMMON :PENTIUM3 :FFI :PREFIXED-API)
>   > (float-sign -0.0)
>   0.0
> 
> 
> The correct value is -1.0.
> 

It seems that ECL does not support -0.0 (at least on input), which
is pretty reasonable thing for Lisp to do:

> (eq 0.0 -0.0)
T

So, the correct value is 1.0.  Another thing is :IEEE-FLOATING-POINT
in the features: I personally would sugesst to have feature called
:IEEE-ROUNDING (or maybe :IEEE-FLATING-FORMAT) to indicate that IEEE
rounding and representation is used.  I believe that most people
when they say that thay want IEEE really want standard format and
rounding rules while other parts starting from signed 0 (especially
Nans and denormals) are pretty controversial.

Of couse, ECL may decide to support signed 0.

-- 
                              Waldek Hebisch
hebisch at math.uni.wroc.pl